1. Field of the Invention
This invention relates to improved biologically pure, novel strains of quick acting general purpose bakers yeast which show good performance in sweet, regular and lean dough systems and especially superior performance in sweet and lean doughs, and methods of obtaining the same from existing strains of quick acting bakers yeast by hybridization via protoplast fusion of petite mutants of such quick acting yeast, to quick acting active dry yeast made from these strains yeast and to improved baking methods using said novel yeast strains in active dry yeast form.
2. Description of the Prior Art
So-called quick acting strains of the yeast Saccharomyces cerevisiae are known and are commercially available in active dry yeast form. These yeasts are generally characterized by the rapid production of a relatively large amount of carbon dioxide in a given time frame when mixed with doughs which basically contain flour and water, and which usually fall into one of the general categories of sweet, lean, or regular doughs. The value of these so called quick bakers yeasts are especially significant in the commercial baking field particularly when used in the active dry yeast form containing low amounts, i.e. 4 to 8 percent, of moisture. Some of the quick acting yeasts which are available are characterized by a tolerance to sweet doughs which contain substantial amounts of sugar, i.e., up to about 20 to 25% sugar. Generally speaking, these fast acting, or so called quick yeasts of commerce have only moderate activity with a regular or straight dough which contains 4 to 5% sugar and relatively poor activity in lean doughs which contain no added sugar. Likewise quick lean dough yeast of commerce are not useful for sweet doughs. Actually, it is generally acknowledged in the baking industry that improvements in performance of yeast in sweet dough formulations is at the expense of lean dough performance and vice versa.
This recognition has led to commercial yeast producers manufacturing separate yeast products for commercial use in either sweet doughs or lean doughs. Insofar as it is presently known, there is no single yeast strain which demonstrates quick and superior leavening activity in both lean doughs and sweet doughs.